You’ve said before that girls resent CP and its use with girls causes an increase in misbehavior. I disagree with the first part of that but I accept that resentment would cause children to become uncooperative, which could manifest as misbehaviour.
Sex-discriminatory policies serve no purpose other than to increase disruption and ill-feeling among the victims.
I have a family friend who I’ve known for years who actually lives in Melbourne Australia. A member of his family is a teacher in Melbourne, and when I suggested CP was still in use there they both thought the idea was totally preposterous and haven’t heard of its use for a good many years.